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Disney Research Turns Mo-Cap Inside-Out With Body-Mounted Cameras

By mounting cameras on actors' bodies, Disney hopes to make motion-capture more natural.Images: Disney Research/Carnegie Mellon University

Researchers from Disney's R&D lab want to turn motion-capture inside-out. Instead of pointing an array of cameras at an actor, they propose the performer wear 20 cameras on his or her body.

[partner id="wireduk"]Motion capture – which is used to turn real-life actions and movements into digitized animations for CGI characters – has become a mainstay in Hollywood and game design. But the current setup, where cameras track pingpong-ball-style markers on an actor, has its limitations.

The actor is normally confined to a studio, so capturing a big action like running outside or swinging on monkey bars is tough (if not impossible) for traditional mo-cap systems.

At Siggraph 2011, an annual conference on computer graphics in Vancouver, British Columbia, researchers from Carnegie Mellon University and Disney Research revealed their new take on the idea. Instead of pointing cameras at actor, they put the cameras directly on the performers.

Researchers used velcro to mount 20 lightweight cameras on the limbs and trunk of each performer. The cameras then harnessed a process called "structure from motion," which analyzes the images from the camera to estimate the location and direction of the lens.

A computer algorithm then collates all the data to automatically build a digital skeleton and position its limbs in accordance with the actor. The system even makes a rough 3-D scan of the environment for elements like the floor and handholds, to provide context for the animator.

Right now, the new mo-cap system has some hurdles to overcome. It can take an entire day to process a minute of motion, and it doesn't have the fidelity of traditional motion capture. But Carnegie Mellon professor Takeo Kanade says that fidelity will improve as the resolution of these small video cameras increases.